<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            width: 100%;
            height: 400px;
            background-color: pink;
            display: flex;
        }
        .leftbox{
            width: 100px;
            height: 400px;
            background-color: skyblue;
        }
        .rightbox{
            flex: 1;
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="leftbox"></div>
        <div class="rightbox"></div>
    </div>
</body>
<script>
    //return 只能写在函数体内
    //forEach,map等循环中写return只能阻断本次循环，不能阻断循环外函数的执行，for循环可以
    //async,await修饰的调接口的函数直接用变量接收的话是函数体内return的值
    //if,else,有时需要写完整
    //yield不能写在forEach函数体内
    

//    function fn(){
//     for(var i=0;i<7;i++){
//         console.log(i);
//         if(i>3){
//            return 
//         }
//       console.log(77);
//     }
//    }
//    fn()
//    console.log(44);
var obj={
    a:'2'
}
const {a,b}=obj
console.log(b );
var arr=[1,2,3,4]
console.log(arr.splice(0,3));
console.log(arr   );

</script>
</html> 